Process of making calcium cyanamid.



X No Drawing.

I ject of the King of Experiments mixing process, firstly by I gether withlhe KARL SCHICK, on SIEGEN, Germain.

PROCESS OF MAKING CALCIUM CYANAMID.

Specification of Letters Patent.

Patented Nov. 14., 1911.

To all whom it Jim; concern: Be it known that I KARL Sorr1CK,'a subrussia', German Emperor, residing at Siegen, in the Province of;

Westphalia, Kingdom of Prussia, German.

Empire, have invented certain new and .useful Processes of Making Calclum Cyanamid,

of which the followingis a specification. As is already known, cyanamid or cyanid/ can be obtained by the reaction of nitrogen upon powdered carbid intermingled with powdered halogen salts. The admixture of the halogen-salts in the carbid occasions in industrial working on the large scale a series of drawbacks. It is very difiicult, for instance, to prepare powdered chlorids. ab-, solutely free from water. The slight quan; tities of moisture which are absorbed by calcium chlorid for instance during the pul verizing, decompose corresponding quantities of the carbid in the mixing machine, so that explosions may easily be occasioned by the liberated acetylene if it is not carefully displaced by inert gases. Moreover the mixing of the substances involves expenditure of labor, apparatus, repairs and motive power. have consequently been made in the view of avoiding this troublesome directly adding the halogen salts to the material serving for the production of the ca'rbid, and secondly by adding gradually and in corresponding quantities the halogen salts to the hot molten carbid as it flows from the furnace. The first plan of fusing the halogen salts tocarbid in the furnace gave a serviceable result, but occasioned a number of'troublesome effects in the production of the carbid. The second plan on the other 40 hand resulted very satisfactorily because the Application filed June 1, 1911. Serial No. 630,665.

molt-en carbid even if they still contained a little moisture. The product obtained in this latter way needs only to be cooled so far that it becomes solid. It then, the still brightly red hot mass be'put into a suitable pulverizing machine and treated therein immediately with. nitrogen, then the nitrogen is eagerly absorbed with the-well known reactions. In this manner there is obtained a product equal in value to that obtained by the process hitherto usual. I

The technical and financial advantages of the new process are obvious. The subsequent mixin of the carbid with the halogen salts is avoi ed; these latter salts moreover do not need to be absolutely dry because the carbid flowing out of the carbid furnace is not decorn osed by the moisture contained in the halogen salt at' its high temperature. Further there is avoided as compared with the old I process, the renewed heating of thecarbid mixture, the presence ofgthe dangerous acetylene gas is avoided. 4 y

What I claim is The process ofmaking calcium cyanamid from-carbids and nitrogenby gradually ad ing to the molten carbid flowing out of the carbid furnace, predetermined quantities of halogen salts, then, after cooling until solid, pulverizing the mixture and treating'it with nitrogen while still red hot.

.In testimony, whereof I have signed my name to this specification in the presence of two-subscribing witnesses.

KARL SCI-TICK.

Witnesses:

M. Knnrrnns, GERTRUD BONA.

halogen salts'mingled intimately with the.

and finally 

